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Title: Effect of dissolved noncondensables on liquid forced convection in microchannels

A method of quantifying the effect of noncondensable desorption on the forced flow of liquids in microchannels subject to a uniform heat flux has been developed. The model is based on the solution of the differential forms of the mass, momentum, energy and noncondensable species conservation equations assuming that the liquid is fully saturated with the noncondensable at the channel inlet. Parametric calculations for conditions encountered in typical microchannel experiments were performed and the results presented. The resulting calculations show that significant noncondensable desorption can take place in microchannel flow resulting in increased liquid velocities and enhanced heat transfer. Experiments were also performed with a 0.76 mm diameter microchannel using both fully degassed water and water saturated with air at the channel inlet. The measured heat transfer coefficients for the air-saturated data were significantly higher than for the fully degassed data in regions where the model predicts significant noncondensable desorption. The forced turbulent convective flow of water in microchannels offers a wide variety of applications including micro-electronic cooling, miniature refrigeration, micro heat exchanger systems and the cooling of fission reactor cores.
Authors:
; ;
Publication Date:
OSTI Identifier:
20002402
Report Number(s):
CONF-990805--
TRN: IM200002%%402
Resource Type:
Conference
Resource Relation:
Conference: 33rd National Heat Transfer Conference NHTC'99, Albuquerque, NM (US), 08/15/1999--08/17/1999; Other Information: PBD: 1999; Related Information: In: Proceedings of the 33rd national heat transfer conference NHTC'99, by Jensen, M.K.; Di Marzo, M. [eds.], [1150] pages.
Publisher:
American Society of Mechanical Engineers, New York, NY (US)
Research Org:
Georgia Inst. of Tech., Atlanta, GA (US)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; FORCED CONVECTION; LIQUID FLOW; PARAMETRIC ANALYSIS; TWO-PHASE FLOW; DISSOLVED GASES